The man, a Otaki local, is known to the victim.
Police are not looking for anyone else in relation to the man's death.
The investigation is ongoing and there will be an increased police presence in Otaki over the coming days.
A scene examination will continue tomorrow.
Neighbours of the suspected homicide victim say he was a "really nice guy" who lived a quiet life.
One neighbour said the victim was a quiet man he had spoken to a few times in passing and never had any problems with.
"We didn't communicate much at all, really. He kept to himself and I kept to myself."
Another neighbour said she lived close enough that she could reach out the window and touch the victim's house, but despite being home last night she heard nothing next door.
The first she knew of the death was when she woke up this morning to see the house "alive with police".
"We live in a quiet little town," she said.
"I'm surprised because I didn't see him very often, but he was a nice guy. There was a couple of nice other people."
She said the man rented rooms out in his home, and a new renter had just moved in recently.
A scene examination by police and ESR has been ongoing today, and is expected to continue into tomorrow.
Police confirmed they were treating the death as a homicide.